1. Field of the Invention
The present invention relates to a vector pattern processing circuit for a bit map display system.
2. Description of the Related Art
Bit map display systems are used for displaying a variety of display patterns, including characters, vectors, etc., on a display unit, such as a cathode ray tube (CRT) display unit. Previously, data was stored in a video memory consisting of a plurality of words, each word composed of a plurality of bits, and each bit corresponding to a dot or a picture element in the CRT display unit. The stored data was displayed on the CRT display unit by, for example, raster scanning.
In the bit map display system, a vector pattern processing circuit generates dot data in response to a start coordinate and an end coordinate and stores the data in the video memory. A variety of figures and patterns can be expressed by combining a variety of vector patterns, and therefore, the vector pattern processing circuit is frequently used for generating a variety of patterns.
The prior vector pattern processing circuits, however, suffer from the disadvantages of a low speed, an irregular timing control, and a complex circuit construction. These disadvantages will be described later with reference to the drawings